The Pittsburgh Steelers added depth to their backfield by signing running back Trey Edmunds to the active roster, the team announced Tuesday.

Wide receiver Justin Hunter was placed on injured reserve to open the roster spot for Edmunds, who will join rookie Jaylen Samuels and veteran Stevan Ridley as backups for James Conner.

Conner sustained a right lower leg contusion in Sunday's 33-30 setback to the Los Angeles Chargers on Sunday night. He was injured after being tackled following a reception on a screen pass with 5:08 remaining in the fourth quarter.

The 23-year-old Conner rushed for 60 yards and two touchdowns against the Chargers. He added three receptions for 14 yards for the Steelers (7-4-1), who will visit the Oakland Raiders (2-10) on Sunday (4:25 p.m. ET).

Edmunds was on the practice squad since the start of the season. He is the older brother of safety Terrell Edmunds, the team's first-round pick in April.

The older Edmunds initially was signed by the New Orleans Saints in 2017 as an undrafted rookie free agent from Maryland. He had nine carries for 48 yards and a touchdown in 16 regular-season games.

Hunter sustained a shoulder injury on Sunday, ending his season with three receptions for 21 yards.

The Steelers also signed linebacker Matthew Thomas to the practice squad. Thomas, who originally signed by Pittsburgh as an undrafted rookie free agent from Florida State this year, played in 10 games this season.